Method and apparatus for winding up strands of synthetic filaments



July .3, 1956 A. WURMLI 2,753,125

METHOD AND APPARATUS FOR WINDING UP STRANDS OF SYNTHETIC FILAMENTS Filed Aug. 9. 1954 Fig. 4

IN V EN TOR.

A RTHUR WURML/ ATTORNE United States Patent METHOD AND APPARATUS FOR WINDING UP STRANDS 0F SYNTHETIC FILAMENTS Arthur Wiirmli, Winterthur, Switzerland, assignor to J oh. Jacob Rieter & Co., Ltd., Winterthur, Switzerland, a corporation of Switzerland Application August 9, 1954, Serial No. 448,450 Claims priority, application Switzerland August 10, 1953 4 Claims. (Cl. 242-18) The present invention relates to a method and apparatus for winding-up continuous filament strands on a sleeve mounted on a swingable lever, adapted to press the sleeve and the package formed thereon against a driving surface winder drum.

On account of the frictional engagement produced by the pressing action between the package and the winder drum, the package assumes the same peripheral speed as the drum, and thus winds the strands on to its surface. In order to obtain a satisfactorily wound package, the pressure between the drum and the package has to remain within certain limits. A suitable lever arrangement, together with adjustable weighting or spring means, nearly always compensates for any pressure variations, due to the growth of the package while being wound.

At the initial stage of the winding operation, when none or few complete layers of strand are completed on the package sleeve, the frictional engagement between the package and the surface winder drum differs substantially from the frictional engagement available at a later stage of the winding operation, since no elastic intermediate layer with a higher frictional coefficient is on the sleeve at the beginning of the winding operation. Furthermore, the package cannot, at this stage, be evenly supported along the entire length of the drum, and so the rotation of the yarn is not uniformly transmitted to the package, a fact that disturbs the starting operation, and thus entails waste and impairs economical operation.

It is an object of the present invention to provide a novel method for producing strand packages on take up machines or winders for continuous filament strands which is simple in construction, inexpensive in cost and effective in operation.

It is another object of the present invention to provide a novel method for starting up the winding operation of strand packages of continuous filament.

A further objective of the present invention is to provide an improved apparatus for winding-up a strand of continuous filaments on to a surface driven strand package sleeve.

Other objectives and advantages of this invention will be apparent from the following descriptions taken from the accompanying drawing wherein:

Fig. 1 illustrates an apparatus for carrying out the process of the present invention.

Fig. 2 shows a modification of the apparatus of this invention.

Fig. 3 is a diagram showing the pressure between the surface winder drum and the package plotted as ordinate vs. the size of the package as abscissa, as it presents itself on a conventional machine.

Fig. 4 shows a diagram in which the pressure on the package, produced exclusively by a magnet, is plotted against the size of the package.

Fig. 5 is a diagram showing the pressure obtained by a combination of conventional and novel means, according to this invention.

2,753,125 Patented July 3, 1956 A group of filaments emerging from a spinneret, not shown, is collected in a strand 1 (Fig. 1) and passes through a split drum 2, traversing the strand along the package and thereby controlling an application of layers on to the package sleeve 3. This sleeve, being freely and rotatably mounted on a swingable lever 4 applies, when in an operative position, slight pressure on to the surface of a winder drum 5, rotating in counterclockwise fashion. Due to the frictional engagement resulting from the application of said pressure, the package sleeve takes up the same speed as the peripheral speed of the surface winder drum 5, so that the winding speed corre sponds to the peripheral speed of the surfacewinder drum 5.

The weight of lever 4, as well as that of package 3, is counter-balanced by an adjustable counter-weight 6. The adjustment may be managed by means of a nut fitted on to a threaded extension 7 of lever 7 which pivots on an axle 10, the same axle applies to lever 4. Both levers 4 and 7 are adjustably interconnected by means of a locking screw 9. Appropriate adjustment of these two levers in respect of one another lies in the selection of a determined centre of gravity of the interconnected lever system. The location of the centre of gravity mentioned is preferably selected in such a manner that one component of the force of gravity is directed towards the surface winder drum 5, thus producing the necessary pressure, the reaction thereof being the pressure against the package itself. On account of the increasing size of the package during the winding process, this reaction is subject to change, provided that the centre of gravity is set not to coincide with the centre of axle 10.

For any choice of position of weight 6, as well as lever 4, in respect to lever 7, a predetermined pressure curve, as represented by curves a, b or c in Fig. 3, can be obtained. A similar pressure curve could also be brought about by replacing the weight 6 by an adjustable spring acting between lever 4 and a machine frame 13.

On bracket 14 (Fig. 1), fixed to the machine frame 13, rests an electromagnet 15. An armature 16 is rigidly connected to lever 4 in such a position so as to face electromagnet 15 when the bracket sleeve 3 on lever 4 is moved to its extreme right position. The distance be tween the magnet 15 and the armature 16 is sufficiently small to cause strong attraction between the two. It can readily be seen that in this manner this attraction creates a considerable increase in pressure between package sleeve 3 and surface winder drum 5, as long as the electromagnet 15 remains in close proximity of the armature 16.

Referring now to Fig. 2, a permanent magnet 17 is secured to the lever 4 and an armature 18 is mounted on the machine frame 13 in such a manner that magnet 17 directly faces the armature 18 at the initial stage of the winding operation.

As is well known in the art and is indicated in Fig. 4, the attraction between an armature and an electromagnet, or a permanent magnet decreases rapidly as the spaces between the two become wider; a slight increase in the diameter of the package practically neutralises the influence of magnet 15 or 17 respectively, and the force responsible for additional pressure between the package sleeve 3 and the drum 5 approaches zero as soon as a few layers of strand are wound on to the package sleeve 3.

In Fig. 5, showing the curves a, b and c, resulting from a superposition of those shown in Fig. 3 and Fig. 4, the pressure is extremely high at the start of the winding operation, or upon application of a very few basic layers. Upon conclusion of a small number of basic layers, the pressure follows a course as if no magnet had been installed in the machine.

In this manner, it became possible to increase the pressure on the package at the initial stage of the winding operation to such an extent so as to ensure uniform rotation of the package at the critical initial stage. After this critical stage the pressure is reduced to a level determined by the improved frictional conditions then prevailing.

While I have shown and described specific embodiments of my invention, it will be apparent to those skilled in the art that various changes, modifications, substitutions, additions and omissions may be made therein without departing from the spirit and scope of my invention as set forth in the appended claims.

I claim:

1. An apparatus for winding-up a strand of synthetic filaments, comprising a yarn receiving means, a positive- 1y driven surface winder drum, a weighting system responsible for applying pressure between said yarn receiving means and said surface winder drum, when the yarn receiving means is in operative position, and magnetic means adapted for substantially increasing said pressure at the initial stage of the winding operation, and While the winding operation advances, reducing said pressure to the magnitude produced by the weighting system.

2. An apparatus for winding-up a strand of synthetic filaments, comprising a freely rotatable yarn receiving sleeve, a swingable lever supporting said sleeve, a surface winder drum so positioned as to allow the sleeve on the lever to be brought into contact with said drum, a weighting system normally producing sufliciently large pressing action upon establishing contact with the drum to ensure positive rotation of the yarn receiving sleeve, 'and magnetic means for substantially increasing said pressing action at the initial stage of the winding operation.

3. An apparatus for winding a strand of textile material, comprising a freely rotatable strand receiving sleeve, a swingable lever carrying said sleeve, a positively driving winder drum rotating at a speed that corresponds to the wind up speed, said lever being adapted to be brought into surface driving engagement with said winder drum, means for maintaining pressure sufficiently great to ensure positive driving engagement upon application of several layers of strand, and magnetic means for adding considerable pressure at the beginning of the winding operation due to the absence of uniform frictional conditions between the sleeve and the surface winder drum.

4. A method of winding a strand of a textile fibre material on a sleeve, comprising pressing the sleeve against a surface winder drum by a mechanical force, and superposiug a magnetic force on the mechanical force during the initial stage of the Winding operation which magnetic force rapidly diminishes as the Winding operation proceeds.

References Cited in the file of this patent UNITED STATES PATENTS 1,458,495 Morrison et al June 12, 1923 

1. AN APPARATUS FOR WINDING-UP A STRAND OF SYNTHETIC FILAMENTS, COMPRISING A YARN RECEIVING MEANS, A POSITIVELY DRIVEN SURFACE WINDER DRUM, A WEIGHTING SYSTEM RESPONSIBLE FOR APPLYING PRESSURE BETWEEN SAID YARN RECEIVING MEANS AND SAID SURFACE WINDER DRUM, WHEN THE YARN RECEIVING MEANS IS IN OPERATIVE POSITION, AND MAGNETIC MEANS ADAPTED FOR SUBSTANTIALLY INCREASING SAID PRESSURE AT THE INITIAL STAGE OF THE WINDING OPERATION, AND WHILE THE WINDING OPERATION ADVANCES, REDUCING SAID PRESSURE TO THE MAGNITUDE PRODUCED BY THE WEIGHTING SYSTEM. 